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Came here to say this - transmission overheating in 4H is pretty common on a slow speed climb. This is why 4L exist.
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2025 4Runner Transmission Overheating on Climbs Off-Road
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I do not disagree. But in paved roads?? That would be pretty unsafe. Last time I had a civic or Mazda, they did not have a 4lo and they were able to go up paved hwy climbs at lower speeds (20-45mph) without ever moving the tranny temp needle.
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OP said off road - slow speed over rocks...I do not disagree. But in paved roads?? That would be pretty unsafe. Last time I had a civic or Mazda, they did not have a 4lo and they were able to go up paved hwy climbs at lower speeds (20-45mph) without ever moving the tranny temp needle.
20-45 is not slow speed.
sub 10 mph is slow.
Subbed, just did a 2100 ft climb elevation gain and down. Started at around 3500ft up to 5600ft. Dirt road with minor obstacles to where I had to slow down. Took about 1.5 hours of paved road to get there so everything was well warmed up by the time I hit the dirt road. I had it in 4H most of the time up.
Total 4H drive time was about 45 mins, stock tires, stock everything and minimal weight, not towing. Outside temp 80s. Speed 10-20mph slowing down for obstacles ~8 times or so..
I didn't notice any temp increase but I wasn't looking for it either. I did have my gauge on the oil/trans temp menu though so I would have noticed it if it went up high. I will be more attentive to it from now on.
Total 4H drive time was about 45 mins, stock tires, stock everything and minimal weight, not towing. Outside temp 80s. Speed 10-20mph slowing down for obstacles ~8 times or so..
I didn't notice any temp increase but I wasn't looking for it either. I did have my gauge on the oil/trans temp menu though so I would have noticed it if it went up high. I will be more attentive to it from now on.
one stupid question, do you have your AC on or off?
Our vehicle should have the intergrated tranny cooler linked to the Radiator, I wonder with AC on and force the fan to turn will that lower the temp at low speeds.
Our vehicle should have the intergrated tranny cooler linked to the Radiator, I wonder with AC on and force the fan to turn will that lower the temp at low speeds.
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On mine was on.
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Yea it's just challenging cuz I am not sure how many people are actually taking these things off road up mountains (yet, I know the 6th gen just came out). I got the same response from the dealer and Toyota to put it in S mode or 4L, I will say at least my dealer seems to actually care and thinks that it sucks and agrees that the temps are too high and this could do further damage and would like to see a fix as well. I am going to keep on Toyota because you are right and as others have alluded to, we should be able to go up a mountain especially one that a honda civic could get up. I have more faith in my accord to get up a mountain than I do my 4Runner at this point, that thing at least got me over the Smokies off roadAgree with you, the more people come forward the better. What I have found out is that a lot of people are in denial and keep saying to just put it in Manual Shift or 4LO. But when you have honda Civics reaching the top of the summit and you are on the side of the road pretending to look at the view while waiting for the tranny to cool down on your 70K + vehicle, is very embarrassing to say the least. Let's hope Toyota does something about it.
For now I am just having them exchange the Fluid so that it stays on the record.
And Yes, the assigned it a TAS number. Boyh the dealer and Toyota cases have been close with the conclusion that the owner is not right and 250F are normal temps.
Thank you too for also trying!!!
Recently went from about 6k elevation to 10k elevation offroad mostly in 4hi. Kept waiting on the transmission to get hot based on this thread and other reports but it still hasn't happened to me. Definitely seems like an issue buy maybe not one that affects all vehicles.
I just had this happen again the other day. On a pretty easy dirt road with top speeds of about 20mph. After a mile the temp started climbing. I let it cool when the gauge got to to about 3/4 but I’m sure it would have just kept climbing. I also checked my transmission fluid last night and feel like it looked a little too dark for 6k miles.
I found out that there are 4Runners with trans thermostats and models without. Mine does not have a thermostat. Do you guys have one? Also attached is a pic of the road I was on to give you guys an idea. All my previous Toyotas never had an issue with the temp getting too hot in 4hi on this same road.
I found out that there are 4Runners with trans thermostats and models without. Mine does not have a thermostat. Do you guys have one? Also attached is a pic of the road I was on to give you guys an idea. All my previous Toyotas never had an issue with the temp getting too hot in 4hi on this same road.
